Resilient
While sustainable refers to what can be controlled, resilient refers to being able to continue in spite of threats that can not be controlled, possibly suffering heavy losses but maintaining the capability to continue. In a long term setting resilience is doubtful as it is a question of time until a threatening event becomes large enough as to endanger even the most resilient system. Creating robust, resilient system(s) of civilizations is desireable, but does not relieve from the task to get as much as possible within control and making it sustainable. The two complement each other. Where resilience is used as a concept to avoid taking control and avoiding painful action, as is tempting with climate destabilization, it is counterproductive.
Resilience is a new term, not yet as extensively misused and frustrated as sustainable. It may be the next big thing, but that doesn't make it resistent to being misused.